xhr interception

xhrInterception.js

(function (open) {
XMLHttpRequest.prototype.open = function (method, url, async, user, pass) {

   this.addEventListener("readystatechange", function () {
      let state = this.readyState;
      console.log(this);
      if (this.readyState === 4) {                    
        //here you go
      }
   }, false);

   open.call(this, method, url, async, user, pass);
};

})(XMLHttpRequest.prototype.open);